:Product: 0531RSGA.txt :Issued: 2017 May 31 2200 UTC # Prepared jointly by the U.S. Dept. of Commerce, NOAA, # Space Weather Prediction Center and the U.S. Air Force. # Joint USAF/NOAA Solar Geophysical Activity Report and Forecast SDF Number 151 Issued at 2200Z on 31 May 2017 IA. Analysis of Solar Active Regions and Activity from 30/2100Z to 31/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C1 event observed at 31/1848Z. There are currently 0 numbered sunspot regions on the disk. IB. Solar Activity Forecast: Solar activity is expected to be very low with a chance for a C-class flares on days one, two, and three (01 Jun, 02 Jun, 03 Jun). IIA. Geophysical Activity Summary 30/2100Z to 31/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 538 km/s at 31/0054Z. Total IMF reached 8 nT at 31/2058Z. The maximum southward component of Bz reached -3 nT at 31/1608Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 624 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet levels on day one (01 Jun), quiet to unsettled levels on day two (02 Jun) and quiet to active levels on day three (03 Jun). III. Event probabilities 01 Jun-03 Jun Class M 05/05/05 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 31 May 074 Predicted 01 Jun-03 Jun 075/076/077 90 Day Mean 31 May 076 V. Geomagnetic A Indices Observed Afr/Ap 30 May 006/006 Estimated Afr/Ap 31 May 004/005 Predicted Afr/Ap 01 Jun-03 Jun 005/005-009/010-011/014 VI. Geomagnetic Activity Probabilities 01 Jun-03 Jun A. Middle Latitudes Active 10/15/25 Minor Storm 05/05/10 Major-severe storm 01/01/01 B. High Latitudes Active 15/15/15 Minor Storm 15/20/20 Major-severe storm 15/15/20